what laws govern the quantity and types of energy emitted by an object?
TRANSCRIPT
WHAT LAWS GOVERN THE QUANTITY AND TYPES OF ENERGY EMITTED BY AN OBJECT?
WHAT LAWS GOVERN THE QUANTITY AND TYPES OF ENERGY EMITTED BY AN OBJECT?
In particular:1) The Sun, our source of energy.2) The Earth, which must ultimately lose the energy it receives, or get warmer.
WHAT LAWS GOVERN THE QUANTITY AND TYPES OF ENERGY EMITTED BY AN OBJECT?
In particular:1) The Sun, our source of energy.2) The Earth, which must ultimately lose the energy it receives, or get warmer.
TWO BASIC QUESTIONS:1) HOW MUCH ENERGY?2) WHAT TYPE OF ENERGY?
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic Radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• Hot objects emit more radiation than cold
objects.
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• Hot objects emit more radiation than cold
objects.
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• Hot objects emit more radiation than cold
objects.
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• Hot objects emit more radiation than cold
objects.
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• Hot objects emit more radiation than cold
objects.
How Much Energy?
• Stefan-Boltzman’s Law:• Electromagnetic radiation generated by the
vibration of molecules of a substance.• Average energy level (vibration) of the molecules
in an object is determined by its temperature.• Hotter objects - more vibration• More vibration – more electromagnetic radiation• “Hot objects emit more radiation than cold
objects.”
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1 Δ Energy =15
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1 Δ Energy =15Δ Temp =1
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1 Δ Energy =15Δ Temp =1
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1 Δ Energy =15Δ Temp =1 Δ Energy =65
How Much Energy?
• Stefan-Boltzman’s Law:
E = d.T4
E = Total energy emittedT = Surface temperature of the radiating objectd = Stefan-Boltzman’s constant5.86 x 10-8 (Don’t need to remember!)
Hot objects emit a disproportionatelylarge quantity of energy.
1x1x1x1 = 12x2x2x2 = 163x3x3x3 = 81
Δ Temp =1 Δ Energy =15Δ Temp =1 Δ Energy =65
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths
What Type of Energy?
• Wein’s Law• Electro-magnetic radiation is emitted in a wave form as the
nucleii vibrate.• Waves are characterized by the distance between two
consecutive wave peaks, their “wavelength”.• Hot objects have a greater average energy level in their
molecules.• They vibrate more frequently, so the distance (time)
between peaks becomes shorter.• Hot objects emit most of their energy at short wavelengths,
cool ones emit it at longer wavelengths.
Distance (microns)
0 100 200 300 400 500 600 700 800 900 1000
0
Time
0 5 10 15
Dis
plac
emen
t of E
lect
rons
0
COOL MOLECULE
Distance (microns)
0 100 200 300 400 500 600 700 800 900 1000
0
Time
0 5 10 15
Dis
plac
emen
t of E
lect
rons
0
COOL MOLECULEWavelength
Distance (microns)
0 100 200 300 400 500 600 700 800 900 1000
0
Time
0 5 10 15
Dis
plac
emen
t of E
lect
rons
0
COOL MOLECULEWavelength
HOT MOLECULE
Distance (microns)
0 100 200 300 400 500 600 700 800 900 1000
0
Time
0 5 10 15
Dis
plac
emen
t of E
lect
rons
0
COOL MOLECULEWavelength
HOT MOLECULE
What Type of Energy?
• Wein’s Law:
Wmax = T/2898
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
T = 289.8
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
T = 289.8 Wmax = 2898/289.8 = 10.0μ
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
T = 289.8
T = 1499
Wmax = 2898/289.8 = 10.0μ
What Type of Energy?
• Wein’s Law:
Wmax = 2898/T
Wmax = Wavelength at which an object emits the maximum quantity of its energy, but not exclusively so.
T = Surface temperature of the radiating object.
T = 289.8
T = 1499
Wmax = 2898/289.8 = 10.0μ
Wmax = 2898/1499 = 2.0μ
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun
Earth
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000
Earth 280
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106
Earth 280
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106
Earth 280 360
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106 0.5
Earth 280 360
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106 0.5
Earth 280 360 10
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106 0.5
Earth 280 360 10
Short In
SUN AND EARTH
Surface Energy Wmax
Temp (Wm-2) (μ)
Sun 6000 72.3x106 0.5
Earth 280 360 10
Short In
Long out
RANGES OF TEMPERATURESON EARTH
Temperature (°F)
-40 -20 0 20 40 60 80 100 120
To
tal
En
erg
y E
mit
ted
(Wm
-2)
100
200
300
400
500
600
700
Wav
elen
gth
of
Max
imu
mE
ner
gy
Em
issi
on
( )
8
9
10
11
12
13
Total EnergyEmittedWavelength ofMaximum EnergyEmission
Dr. Waylen's Personallowest temp. Saskatoon
Dr. Waylen's Personalhighest temp. Grand Canyon
Summer dayGainesville
Winter dayGainesville
1 2 3 4
1
2
3
4
4
3
2
1
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALES
Fahrenheit
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Boils
212°F
Water Freezes
32°F
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Boils
212°F
All MoleculesCease Vibrating
-465°F
Water Freezes
32°F
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
Water Boils
212°F
All MoleculesCease Vibrating
-465°F
Centigrade0°C 100°C-273°C
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
Water Boils
212°F
All MoleculesCease Vibrating
-465°F
0°C 100°C-273°C
0°K
KELVIN (Absolute)
E = d. 04 = 0 : No temp, no vibration, no energy
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
Water Boils
212°F
All MoleculesCease Vibrating
-465°F
0°C 100°C-273°C
0°K
KELVIN (Absolute)
Centigrade increments
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
Water Boils
212°F
All MoleculesCease Vibrating
-465°F
0°C 100°C-273°C
0°K
KELVIN (Absolute)
Centigrade increments 273°K
+ 273
0 50 100 150 200 250 300 350 400
-250 -200 -150 -100 -50 0 50 100
-400 -300 -200 -100 0 100 200
TEMPERATURE SCALESWater Freezes
32°F
Water Boils
212°F
All MoleculesCease Vibrating
-465°F
0°C 100°C-273°C
0°K
KELVIN (Absolute)
Centigrade increments 273°K 373°K
+100